Identification
A long white day is followed by a black candle which gaps in the direction of the trend. The final day engulfs the small black day and closes within the gap of the first two days.

The Psychology
In an uptrend or within a bounce of a downtrend, successive gaps up which close down to force a black candle to form suggests the bulls are weaken. They are not able to rally the stock intraday and the bears are starting to take over. The reliability of the increases if the gaps up bump into resistance.

Here is an example of reversal pattern that would be better used to exit a long position rather than initiating a short. After all, the stock had just bounced on big volume. The prudent trader would look to exit a long position and then rebuy the dip.